Drive sprocket for wide chain of drum cutting head

ABSTRACT

A mining machine cutting structure consisting of a single centrally located cutter supporting chain and cutter supporting rotary elements extending outwardly from the sides of the cutter supporting chain.

United States Patent [is] 3,697,136 Teeter [451 Oct. 10, 1972 [54] DRIVE SPROCKET FOR WIDE CHAIN [56] References Cited 0F DRUM C ING HEAD UNITED STATES PATENTS 72 Inventor: Geo e R. Teet 111 G1 Oil 1 f" env'ew 3,305,273 2/1967 Kilboume ..299/76 x 2,650,812 9/1953 Joy ..299/83 [22] Filed: Feb. 17, 1971 2,676,005 4/1954 Joy ..299/83 [211 App 115 965 1,446,292 2/1923 George ..74/247 X Related Application Data Primary Examiner-Ernest R. Purser Attorney-E. Wallace Breisch [62] Division of Ser. No. 786,650, Dec. 24, 1968,

Pat. No. 3,614,162. [57] ABSTRACT A mining machine cutting structure consisting of a sin- C(ii "299/13i g centrally located cutter Suppomng chain and 5 i 4 cutter supporting rotary elements extending outwardly from the sides of the cutter supporting chain.

9 Claim, 2 Drawing Figures PATENTEDnm 10 1972 sum 1 [If 2 IN VEN TOR GEOFEE R. TEETER PMENTEDBM I0 m2 SHEET 2 [1F 2 N QE INVENTOR. GEORGE R. TEETER DRIVE SPROCKET FOR WIDE CHAIN OF DRUM CUTTING HEAD This application is a division of application Ser. No. 786,650 filed Dec. 24, 1968, now US. Pat. No; 3,614,162 and is filed pursuant to an Examiners requirement for restriction under 35 USC 121.

in in a continuous mining apparatus of the type employed in this invention a disintegrating head mechanism or cutting structure is used to dislodge mineral from a mine vein and is operable to provide a mine passageway or room into which the apparatus advances as mining progresses. The disintegrating head mechanism is pivotally mounted on a mobile base to swing in a vertical plane between the mine roof and floor and includes a rotary drum cutting head assembly arranged on a horizontal transverse axis and having teeth or bits which tear away and dislodge the mineral. The apparatus also includes a conventional loading head for gathering the loose mineral on the mine floor and moving it rearwardly and inwardly toward the forward receiving portion of the conveying means of the apparatus. The rotary drum cutting head assembly has end portions thereof which can be selectively extended or retracted to, respectively, dislodge mineral from the ribs and corners of a mine passageway and reduce the effective length of the cutting head assembly to provide clearance at the sides of the assembly.

The present invention contemplates improvements over such known types of mining apparatus, for example; an improved rotary drum cutter head assembly configuration which allows the use of a centrally located relatively wide endless circulating cutter chain; and chain support surfaces on the drum head portions.

These and other objects and advantages of this invention will become more readily apparent from the following description and drawings in which:

FIG. 1 is a perspective view of a mining machine embodying the principles of this invention;

FIG. 2 is an enlarged view, partly in section, taken on line 2-2 of FIG. 1 and showing a main gear casing and a portion of the cutter head assembly embodying the principles of this invention.

A continuous mining machine generally designated at 10, which embodies the principles of this invention, may assume various forms but, for illustrative purposes, herein comprises a crawler base 14 carrying a frame 16 on which a forwardly extending mining boom 18 is pivotally mounted at the forward end of the frame 16 to swing up and down between a mine roof and a mine floor. A cutting head assembly 24 extends transversely A of boom 18 and is rotatably secured thereto at the forward end thereof. Pivotably mounted at the forward end of frame 16 and extending forwardly therefrom beneath the boom 18 is a conventional loading head 26 having oscillatory gathering arms 28 for engaging mined mineral and moving such mineral rearwardly and inwardly toward well known conveying means 30 of the mining machine 10. Conventional fluid jacks serve to swing the boom 18 in a vertical plane about the pivot axis thereof and the loading head 26 is tilted about the horizontal axis thereof by other fluid jacks. The fluid jacks have one end of each secured to the forward end of frame 16 and have the other ends thereof secured to respective rearward lever ends of boom 18 and loading head 26.

The cutting head assembly 24 is driven from motors 36, which are suitably rigidly secured by brackets to boom 18. The drive from motors 36 is delivered through speed reducing transmissions to a pair of universal drive shafts 42. Inasmuch as the gearing arrangement from both drive shafts 42 to the cutting head assembly 24 is identical, the discussion hereinafter will refer to the drive train from a single drive shaft 42.

The end of drive shaft 42 is suitably connected by shafts and bevel gears to a shaft 52 which extends transversely inward of machine 10 and is suitably rotatably supported by a bevel gear casing 54 mounted on the boom 18. Bevel gear casing 54 is suitably secured to a side portion of a main gear casing 56. Casing 56 is contained within a forward area of boom 18 and is securely fastened to the inner sides thereof in any suitable manner.

The shaft 52 has a spur gear 58 at the inner end thereof which is drivingly connected through a series of gears with a reduction gear 68 in driving engagement with a splined portion of a cutting head assembly drive shaft 70. Shaft 70 extends through gear 68 in a transverse direction with relation to the longitudinal axis of mining machine 10. Gears 58-68 and a portion of shaft 70 are captively and rotatably received by gear casing 56.

Shaft 70 is rotatably supported by tubular gear casing extensions 72 which extend outwardly [i.e. transversely from the centerline of machine 10 from a forward portion 74 of gear casing 56. As hereinafter described in detail shaft 70 rotatably drives: an endless circulating belt type continuous hinge cutter chain 76 which has a width thereof approximately equal to a transverse measurement of a forwardly extending casing portion 74 taken at the forward end thereof; hollow cylindrical rotary drum cutting heads 78 which extend outwardly away from respective sides of portion 74; and hollow cylindrical rotary drum cutting head extensions 80 [see FIG. 1] which are slidably partially received within respective heads 78 and are selectively hydraulically extendable outwardly therefrom.

At the longitudinal centerline of machine 10 a cutter chain drive sprocket 82 is in splined engagement with shaft 70. Drive sprocket 82 has a plurality of teeth 84 around the outer periphery thereof which drivably engage the cutter chain 76 as hereinafter described. A suitable rear idler sprocket 86 which is rotatable on a shaft 88 and extends transversely of the forward boom area, provides well known tensioning and motion reversing means for the cutter chain 76 to form a continuous orbital path therefor.

Spacer sleeves 90 are positioned along shaft 70 intermediate sprocket 82 and adjacent gears 68 so as to maintain a spaced relationship between sprocket 82 and gears 68. On the outer sides of gears 68 [outer being away from sprocket 82 along the centerline of shaft 70] spacer sleeves 92 are positioned along shaft 70 to provide a spaced relationship between gears 68 and roller bearings 94 which additionally surround shaft 70. Roller bearings 94 provide a rotational relationship between the main gear casing 56 and shaft 70 inwardly adjacent the outer ends of casing extension portions 72. A spacer sleeve 96 is positioned along shaft 70 outwardly adjacent the bearings 94. The outer diameter of spacer sleeve 96 is less than the outer diameter of bearing 94. Annular drive shaft keepers 98, which are rigidly secured to the outer ends of casing extension portions 72 and project radially inwardly from the inner periphery thereof, have the inner surfaces thereof in rotatable contact with the outer surface of spacer sleeves 96.

Outwardly adjacent to spacer sleeves 96 and keepers 98, internally splined rotary drum cutting head driving sleeves 100 are in splined engagement with shaft 70. Sleeves 100 are rigidly secured to the rotary drum cutting heads 78 intermediate the axial ends thereof and project radially inwardly from the inner periphery thereof. with such sleeves 100 the rotary drum cutting heads 78 are rotatably driven from shaft 70 at a rate thereof equal to the rate of cutter chain drive sprocket 82 and cutter chain 76. The inner end of cutting heads 78 (inner end being that end closest to the longitudinal centerline of machine are rotatably supported by roller bearings 102. Bearings 102 are fixedly secured about the outer periphery of casing extension portions 72 adjacent the inner ends thereof.

Outwardly adjacent to sleeves 100, lock nuts 104 are threadably received on shaft 70. When lock nuts 104 are positioned around shaft 70 and tightened into bearing against sleeves 100 at the outer surface thereof: engaging sleeves 100; spacer sleeves 90, 92 and 96, roller bearings 94; and drive sprocket 82 are releasably secured with respect to shaft 70 thereby preventing any motion thereof in the axial direction. Transverse movement of shaft 70 with respect to machine 10 is prevented by lock nuts 104 transferring thrust from shaft 70 through the sleeves 100 and the remainder of the cutter heads 78 to the bearings 102.

Each rotary drum cutting head 78 has a radially outwardly extending flange 106 at the inner ends thereof and a reduced diameter portion thereof forms a chain end supporting seat 108 which extends axially from flange 106 toward the centerline of machine 10. Seats 108 extend under a portion of the outer edges of the endless circulating cutter chain 76 and with such a location act to support the bight portion of the cutter chain 76 at the edges thereof where it is trained about the rotary drum cutting heads 78. The relative rotational speeds of the cutter chain 76 and the seats 108 are equal and therefore there is no movement of cutter chain 76 with respect to the seats 108 during the time chain 76 is supported by seats 108. Because of this lack of relative movement there is no wearing between the respective contact surfaces of seats 108 and chain 76.

The cutter chain drive sprocket 82 is dimensioned to provide root surfaces 1 10 thereof which lie in approximately the same cylindrical surface as the contact surfaces of the spaced seats 108. With such root surfaces 110, each link in the bight portion of chain 76 is sup ported at three areas, namely: end supports at the contact surfaces of the spaced seats 108; and a central support at a root surface 110 of the drive sprocket 82. With such a support arrangement the deflection of chain 76 is minimized and the maximum bending moment due to cutting loads is reduced over that deflection and bending moment which would develop under the same loading if the chain 76 had only one or two areas of support. This support arrangement allows the use of cutter chains having a greater chain width to pitch length ratio than previously permitted, for example a chain width to pitch length ratio of four to one, or more. Such a large width to length ratio permits the construction of a chain width large enough for the purposes of this invention, i.e. to cut clearance for casing portion 74, while maintaining a sufficient flexibility to avoid unreasonably large chain drive sprocket diameters. If the chain width to pitch length ratio is less than four to one, the required chain width would yield a pitch length requiring sprockets too large to be used in a cutter head such as hereinbefore described.

The cutter chain 76 may be of any suitable construction which incorporates hingedly connected links and is adapted to be driven by a central drive sprocket, as for example that cutter chain shown and illustrated in US. Pat. application No. 786,649, filed Dec. 24, 1968 and assigned to the same assignee as is this invention.

For further description and illustration of the mining machine on which this invention may be employed reference should be had to my copending application Ser. No. 786,750 filed Dec. 24, 1968 of which this application is a division.

It is to be noted that cutter chains designed according to the principles of this invention can be used on mining machines of a type other than the rotary drum mining machine 10 hereinbefore described, for example one or two of such chains can replace the multiple cutter chains of a ripper bar miner of the type illustrated in US. Pat. No. 2,650,813.

Preferred embodiments of the mining machine of this invention having been hereinbefore described and herewith illustrated it is to be realized that variations in the specific structure are envisioned and contemplated as further embodiments of the principles of this invention. It is therefore respectfully requested that this invention be interpreted as broadly as possible and limited only by the scope of the appended claims.

What is claimed is:

l. A cutter head for a mining machine consisting of a pair of axially elongated cutter carrying coaxial drum elements mounted on a common head shaft with an axial space therebetween: a single cutter chain drive sprocket drivingly mounted centrally on said head shaft in said space, said sprocket having teeth only on a central peripheral portion thereof axially spaced from said drum elements and being adapted to drive a cutter chain covering said space.

2. A cutter head as specified in claim 1 wherein said head shaft is hollow; said drum elements include axially extensible drum portions slidably mounted on end portions of said head shaft and connected between said head shaft and the respective drum elements to axially lengthen and shorten said drum elements.

3. A cutter head as specified in claim 1 wherein said drive sprocket has tooth portions thereon separated by root surfaces therebetween; adjacent end portions of said drum elements have arcuate chain support contact surfaces thereon; and said contact surfaces lie in approximately the same cylindrical surface as said root surfaces to provide laterally spaced three point support for such a chain.

4. A cutter assembly for a mining machine comprising the cutter head specified in claim 3 combined with an endless orbitable cutter chain having a chain width to pitch length ratio of at least four to one.

5. The cutter assembly as specified in claim 4 wherein said cutter chain is formed of hingedly connected links and each link in turn is simultaneously supported at said laterally spaced three points through a portion of the orbit of said chain.

6. The cutter assembly as specified in claim 4 additionally comprising an idler sprocket rotatable on an axis laterally spaced from and parallel to the axis of rotation of said drive sprocket said chain being trained about both of said sprockets in a substantially eliptical shape.

7. The cutter assembly as specified in claim 6 wherein said cutter chain drive sprocket is powered to drive said cutter chain in a substantially eliptical orbit having respective bight shaped end portions about said sprockets and each link of said chain is supported at said three points simultaneously through at least a major part of one of said bight portions of said orbit.

8. A cutter head as specified in claim 1 wherein said drive sprocket is equally spaced from said drum elements end portions by spacer elements slidable on the exterior of said head shaft.

9. A cutter head as specified in claim 8 wherein there are two of said spacer elements with a drive gear between mounted on said head shaft on each side of said drive sprocket. 

1. A cutter head for a mining machine consisting of a pair of axially elongated cutter carrying coaxial drum elements mounted on a common head shaft with an axial space therebetween: a single cutter chain drive sprocket drivingly mounted centrally on said head shaft in said space, said sprocket having teeth only on a central peripheral portion thereof axially spaced from said drum elements and being adapted to drive a cutter chain covering said space.
 2. A cutter head as specified in claim 1 wherein said head shaft is hollow; said drum elements include axially extensible drum portions slidably mounted on end portions of said head shaft and connected between said head shaft and the respective drum elements to axially lengthen and shorten said drum elements.
 3. A cutter head as specified in claim 1 wherein said drive sprocket has tooth portions thereon separated by root surfaces therebetween; adjacent end portions of said drum elements have arcuate chain support contact surfaces thereon; and said contact surfaces lie in approximately the same cylindrical surface as said root surfaces to provide laterally spaced three point support for such a chain.
 4. A cutter assembly for a mining machine comprising the cutter head specified in claim 3 combined with an endless orbitable cutter chain having a chain width to pitch length ratio of at least four to one.
 5. The cutter assembly as specified in claim 4 wherein said cutter chain is formed of hingedly connected links and each link in turn is simultaneously supported at said laterally spaced three points through a portion of the orbit of said chain.
 6. The cutter assembly as specified in claim 4 additionally comprising an idler sprocket rotatable on an axis laterally spaced from and parallel to the axis of rotation of said drive sprocket said chain being trained about both of said sprockets in a substantially eliptical shape.
 7. The cutter assembly as specified in claim 6 wherein said cutter chain drive sprocket is powered to drive said cutter chain in a substantially eliptical orbit having respective bight shaped end portions about said sprockets and each link of said chain is supported at said three points simultaneously through at least a major part of one of said bight portions of said orbit.
 8. A cutter head as specified in claim 1 wherein said drive sprocket is equally spaced from said drum elements end portions by spacer elements slidable on the exterior of said head shaft.
 9. A cutter head as specified in claim 8 wherein there are two of said spacer elements with a drive gear between mounted on said head shaft on each side of said drive sprocket. 